move semantics for different qt versions - qt

Question

Am beginner in move semantics and I'm confused by compilation result. When I use qt 5.5.1 all are okey, but when I use qt 4.8.7 I have build errors. I'm trying to build the following code:
struct TResource
{
int _resource_id = 18;
};
typedef std::vector<std::unique_ptr<TResource>> TResources;
struct TChannel
{
QString _title;
TResources _ress;
};
typedef std::vector<TChannel> TChanneles;
int main(int , char **)
{
TChannel channel;
TChanneles chnls;
//Creating some channel resorces and place it to the vector
// .......
chnls.push_back(std::move(channel));
return 0;
}
The error messages are following:
g++ -c -m64 -pipe -std=c++0x -O2 -Wall -W -D_REENTRANT -DQT_NO_DEBUG -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt4/mkspecs/linux-g++-64 -I. -I/usr/include/qt4/QtCore -I/usr/include/qt4 -I. -o main.o main.cpp
In file included from /usr/include/c++/5/bits/stl_tempbuf.h:60:0,
from /usr/include/c++/5/bits/stl_algo.h:62,
from /usr/include/c++/5/algorithm:62,
from /usr/include/qt4/QtCore/qglobal.h:68,
from /usr/include/qt4/QtCore/qnamespace.h:45,
from /usr/include/qt4/QtCore/qobjectdefs.h:45,
from /usr/include/qt4/QtCore/qobject.h:47,
from /usr/include/qt4/QtCore/qcoreapplication.h:45,
from /usr/include/qt4/QtCore/QCoreApplication:1,
from main.cpp:1:
/usr/include/c++/5/bits/stl_construct.h: In instantiation of ‘void std::_Construct(_T1*, _Args&& ...) [with _T1 = std::unique_ptr<TResource>; _Args = {const std::unique_ptr<TResource, std::default_delete<TResource> >&}]’:
/usr/include/c++/5/bits/stl_uninitialized.h:75:18: required from ‘static _ForwardIterator std::__uninitialized_copy<_TrivialValueTypes>::__uninit_copy(_InputIterator, _InputIterator, _ForwardIterator) [with _InputIterator = __gnu_cxx::__normal_iterator<const std::unique_ptr<TResource>*, std::vector<std::unique_ptr<TResource> > >; _ForwardIterator = std::unique_ptr<TResource>*; bool _TrivialValueTypes = false]’
/usr/include/c++/5/bits/stl_uninitialized.h:126:15: required from ‘_ForwardIterator std::uninitialized_copy(_InputIterator, _InputIterator, _ForwardIterator) [with _InputIterator = __gnu_cxx::__normal_iterator<const std::unique_ptr<TResource>*, std::vector<std::unique_ptr<TResource> > >; _ForwardIterator = std::unique_ptr<TResource>*]’
/usr/include/c++/5/bits/stl_uninitialized.h:281:37: required from ‘_ForwardIterator std::__uninitialized_copy_a(_InputIterator, _InputIterator, _ForwardIterator, std::allocator<_Tp>&) [with _InputIterator = __gnu_cxx::__normal_iterator<const std::unique_ptr<TResource>*, std::vector<std::unique_ptr<TResource> > >; _ForwardIterator = std::unique_ptr<TResource>*; _Tp = std::unique_ptr<TResource>]’
/usr/include/c++/5/bits/stl_vector.h:322:31: required from ‘std::vector<_Tp, _Alloc>::vector(const std::vector<_Tp, _Alloc>&) [with _Tp = std::unique_ptr<TResource>; _Alloc = std::allocator<std::unique_ptr<TResource> >]’
main.cpp:11:8: required from ‘void std::_Construct(_T1*, _Args&& ...) [with _T1 = TChannel; _Args = {TChannel&}]’
/usr/include/c++/5/bits/stl_uninitialized.h:75:18: [ skipping 2 instantiation contexts, use -ftemplate-backtrace-limit=0 to disable ]
/usr/include/c++/5/bits/stl_uninitialized.h:281:37: required from ‘_ForwardIterator std::__uninitialized_copy_a(_InputIterator, _InputIterator, _ForwardIterator, std::allocator<_Tp>&) [with _InputIterator = TChannel*; _ForwardIterator = TChannel*; _Tp = TChannel]’
/usr/include/c++/5/bits/stl_uninitialized.h:303:2: required from ‘_ForwardIterator std::__uninitialized_move_if_noexcept_a(_InputIterator, _InputIterator, _ForwardIterator, _Allocator&) [with _InputIterator = TChannel*; _ForwardIterator = TChannel*; _Allocator = std::allocator<TChannel>]’
/usr/include/c++/5/bits/vector.tcc:422:8: required from ‘void std::vector<_Tp, _Alloc>::_M_emplace_back_aux(_Args&& ...) [with _Args = {TChannel}; _Tp = TChannel; _Alloc = std::allocator<TChannel>]’
/usr/include/c++/5/bits/vector.tcc:101:23: required from ‘void std::vector<_Tp, _Alloc>::emplace_back(_Args&& ...) [with _Args = {TChannel}; _Tp = TChannel; _Alloc = std::allocator<TChannel>]’
/usr/include/c++/5/bits/stl_vector.h:932:21: required from ‘void std::vector<_Tp, _Alloc>::push_back(std::vector<_Tp, _Alloc>::value_type&&) [with _Tp = TChannel; _Alloc = std::allocator<TChannel>; std::vector<_Tp, _Alloc>::value_type = TChannel]’
main.cpp:26:39: required from here
/usr/include/c++/5/bits/stl_construct.h:75:7: error: use of deleted function ‘std::unique_ptr<_Tp, _Dp>::unique_ptr(const std::unique_ptr<_Tp, _Dp>&) [with _Tp = TResource; _Dp = std::default_delete<TResource>]’
{ ::new(static_cast<void*>(__p)) _T1(std::forward<_Args>(__args)...); }
^
In file included from /usr/include/c++/5/memory:81:0,
from main.cpp:2:
/usr/include/c++/5/bits/unique_ptr.h:356:7: note: declared here
unique_ptr(const unique_ptr&) = delete;
^
Makefile:203: recipe for target 'main.o' failed
make: *** [main.o] Error 1
It seems that something not supported in qt 4.8.7 and I should take this into account and change my code. But I don't know what change.
Thank you in advance.

Answer 1

I have fixed my issue.
A have added move constructor TChannel struct:
TChannel(TChannel&& that)
{
_title = std::move(that._title);
}
It helped because move constructor was introduced in Qt 5.2.